$A$ recombinant $DNA$ molecule was created by ligating a gene to a plasmid vector. By mistake,an exonuclease was added to the tube containing the recombinant $DNA$. How does this affect the next step in the experiment,i.e.,bacterial transformation?

The process of separation and purification of the expressed protein before marketing is called .........

Which of the following statements are correct with respect to $DNA$ separation, isolation and visualization?
$A$. The cutting of $DNA$ is done by molecular scissors.
$B$. The $DNA$ fragments separate according to their size in an agarose gel, upon electrophoresis.
$C$. The separated $DNA$ fragments can be seen without staining when exposed to $UV$ light.
$D$. The separated $DNA$ fragments, when stained with ethidium bromide, can be seen in visible light.
Choose the correct answer from the options given below:

In $r-DNA$ technology,the term 'elution' refers to:

The figure below shows three steps $(A, B, C)$ of a process. Select the option giving the correct identification $:-$

Diagrammatically represent the experimental steps in cloning and expressing a human gene (e.g.,the gene for growth hormone) in a bacterium like $E. coli$.